[eggjs/egg]service不执行

这是定时任务：

"use strict";

const Subscription = require("egg").Subscription;

class GetProxyIPs extends Subscription {
  static get schedule() {
    return {
      interval: "30s",
      type: "all",
      immediate: false,
      disable: false
    };
  }

  async subscribe() {
    //http://35.245.208.185:3128
    console.log('start proxy');
    const result = await this.ctx.service.api.smth.proxy_ip_pool.getIPs();
    console.log(result);
  }

}

module.exports = GetProxyIPs;

这是service：

"use strict";

const Service = require("egg").Service;

class ProxyIPPoolService extends Service {
  async getIPs() {
    console.log('get ip');
    const result = await this.app.mysql.insert("ip", {
      address: "35.245.208.185",
      port: "3128",
      protocal: "http"
    });

    return result;
  }

  async checkIP(ip) {}

  async saveIP(ip) {}

  async deleteIP(ip) {}
}

module.exports=ProxyIPPoolService;

现在问题是：定时任务里的’start proxy‘可以打印出来，但是service里getIPs()里的’get ip‘，没有打印出来，应该是函数没有执行，请问一下这是什么问题？